Threading a punch tube

[TomE]

I purchased a couple of replacement tubes for an Osborne #153 spring punch, and one of them doesn't screw into the punch.  The threads appear to be shallow and incompletely cut.  I received a replacement tube with the same problem.  While waiting for the vendor to resolve this with CS Osborne, I tried cutting threads on one of the tubes and the metal is hard and brittle (which I'll view as a good thing).  Any advice about removing the temper, cutting threads, and hardening the tube would be appreciated.  I don't own a forge but have an acetylene torch, oven, Zippo lighter, ....  This is an experiment while waiting for Osborne to replace the defective tubes.

[fredk]

I'd try using a fine tri-square file to chase the threads first

[zuludog]

7 minutes ago, fredk said:

I'd try using a fine tri-square file to chase the threads first

Or a knife blade needle file

[chuck123wapati]

if its thin and small enough a soldering torch will heat it enough, the acetylene is plenty also, anneal it cut the threads then reharden bright orange into oil  and temper at about 400 f. the hard part is getting it into the oil at bright orange you only have a second or so. temper it in an oven or toaster oven

here is a video the operation is the same

 

Edited December 24, 2021 by chuck123wapati

[TomE]

Thanks @chuck123wapati!  I'll watch the video after I feed some horses and report back on my results.

[bruce johnson]

If this is an old frame - The old frames were tapped with a shallower tap and the new threads on the replacement tubes are the correct pitch but too high. Chase the threads in the  frame with a new tap of the same size and you will be good without doing anything else. realize they used three sizes of taps - 00-7 used the same, #8 had it's own size, and #9 and #10 had a different one. 

I chase the threads in every single tube punch I do so down the line the new replacement tubes will fit. 

[MikeRock]

Bruce,

Thank you for that.  I had the same problem and recut the threads, a real pain. 

Merry CHRISTmas to all.

Mike and Valerie

 

 

[TomE]

19 hours ago, bruce johnson said:

If this is an old frame - The old frames were tapped with a shallower tap and the new threads on the replacement tubes are the correct pitch but too high. Chase the threads in the  frame with a new tap of the same size and you will be good without doing anything else. realize they used three sizes of taps - 00-7 used the same, #8 had it's own size, and #9 and #10 had a different one. 

I chase the threads in every single tube punch I do so down the line the new replacement tubes will fit. 

Thanks, Bruce.  Good information.  My spring punch is about 5-6 years old, and the 00 replacement tube fit whereas the 0 tube in the same order had shallow threads.  Following advice from @chuck123wapati I annealed the tube, cut in the threads with a 5/16-24 die, hardened and tempered the tube, then cleaned up the cutting edge and polished it.  I had to punch some oiled leather to clean out the exit hole and now I have a working punch.  Thanks to everyone for their input.  It is a privilege to connect with so many experienced leatherworkers here. 

[MikeRock]

If you stick the punch in a potato and heat the threads to orange quickly a few or three times, just the threads will soften and no hardening and tempering is needed.

[TomE]

7 hours ago, MikeRock said:

If you stick the punch in a potato and heat the threads to orange quickly a few or three times, just the threads will soften and no hardening and tempering is needed.

Good tip!  I'll try the potato for the replacement tube that has the same problem with shallow threads.

[chuck123wapati]

10 hours ago, TomE said:

Good tip!  I'll try the potato for the replacement tube that has the same problem with shallow threads.

darn right it is, will work fine that way.

[MikeRock]

Anything will do, apple, orange, you get the idea.

If you want to have fun with a potato, rub the cut surface on American paper money.  Or use spray starch.  The little pen they use in stores to detect counterfeit money is nothing more than an iodine pen.  US paper money does not contain starch, so the iodine won't react.  If there is starch anywhere the iodine reacts with it and turns almost black.   Got this from high school chemistry class.......a LONG time ago.   I daydreamed of slyly spraying cash registers with spray starch when in Vegas once.  It would cause a bloody panic!!   Enjoy! 

God bless

[bruce johnson]

On 12/25/2021 at 9:44 AM, TomE said:

Thanks, Bruce.  Good information.  My spring punch is about 5-6 years old, and the 00 replacement tube fit whereas the 0 tube in the same order had shallow threads.  Following advice from @chuck123wapati I annealed the tube, cut in the threads with a 5/16-24 die, hardened and tempered the tube, then cleaned up the cutting edge and polished it.  I had to punch some oiled leather to clean out the exit hole and now I have a working punch.  Thanks to everyone for their input.  It is a privilege to connect with so many experienced leatherworkers here. 

I was more comparing the threads on a 100 year plus old Newark marked single tube punch vs the Harrisons. Still when I clean one up and sharpen or replace the punch tubes I run a tap through the frame to clean the threads. I screw my punch tubes in to bottom out the tube threads so they wont twist while I am punching also. 

[TomE]

6 minutes ago, bruce johnson said:

I screw my punch tubes in to bottom out the tube threads so they wont twist while I am punching also. 

I had to run the die into the collar of the tube to finish the threads lower on the tube.  By trial and error I found how far to cut threads so they bottom out with the tube squarely contacting the punch anvil.  The tube is firmly seated on the finished threads at this position even though some partial threads are showing.

[bruce johnson]

Gotcha, I haven't run into that much thread showing to meet the anvil.  Just another curiosity question here. Is the frame marked on the other side or have the Osborne maker and size number been ground off. I haven't had that weren't marked on this side that I remember.

[TomE]

Here is the mark. 

[bruce johnson]

Thanks! Have heard about the etched marking but hadn't seen one yet. Appreciate the picture. I have a set of new ones a customer is sending for me to sharpen the tubes and number stamp the top and side of the frame. I know what I'm getting now.